CA1299628C

CA1299628C - Installation method of a kneading trough in an oven and its apparatus

Info

Publication number: CA1299628C
Application number: CA000587098A
Authority: CA
Inventors: Takashi Asahina; Mitsuo Akiyoshi; Yoshio Mitsumoto; Satoru Kodama; Masaharu Tsujimoto
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 1987-12-28
Filing date: 1988-12-28
Publication date: 1992-04-28
Anticipated expiration: 2009-04-28
Also published as: DE3886187T2; EP0322836A2; AU597858B2; DE3886187D1; EP0322836B1; EP0322836A3; AU2755888A; US4870896A; KR910007517B1; KR890009343A

Abstract

Abstract A heating and cooking apparatus has a kneading trough detachably installed in a heating chamber of the apparatus. The trough has a handle for easy carrying by a user. Both the trough and a mounting portion to be engaged by the trough in the heating chamber are non circular, e.g. rectangular. As a result, the force in the direction of rotation during operation can be positively received corners, thus enhancing the strength of the apparatus, and avoid rattling, wear or disengagement of the parts.

Description

~2996æ8 Ia~atra~ustion method of a kneading trough in an oven and its ________________________________________________________, The present invention relates generally to a heating and cooking apparatus having a kneading trough detachably accommodated therein, and, more particularly, to a method of installation and arrangement of the kneading trough in the apparatus.
Conventionally, an oven is used when ~ood is cooked. A kneading device has been employed when the food is to be kneaded. Recently, however, an automatic bread baking apparatus has appeared on the market in which bread can be made automatically by consecutive operations from kneading to baking. Before the advent of this automatic bread baking apparatus, an oven equipped with a kneading arrangement has also been on the market. In this oven, a trough for kneading is accomodated in the oven. This trough should be taken out of the oven, and the kneaded material should be transferred to another trough or plate for fermentation and baking.
The former automatic bread baking apparatus is exclusively used for bread. Therefore, when a variety of breads, such as rolls, croissants, etc. are desired, the apparatus can serve for only a part of a series of the baking operation, namely, kneading and fermentation, requiring an additional oven that is large enough to bake severàl rolls or croissants, etc. at one time.
On the other hand, in the latter oven having a kneading device, whether bread is baked, or one of the . .

~;~996;i~8 other kinds of bread is desired, the material, after finishing partial fermentation, must be transferred to another trough for the baking operation, which results in a complicated and troublesome procedure.
In recent years, it has been propose~ that the three cooking operations of kneadiny, baking and roasting, each conventionally carried out respectively by a kneading device, automatic bread baking apparatus and an oven, should be performed by a single cooking unit. Such a cooking unit can be achieved simply by adding a special trough to the oven, which is advantageous from the space-saving and cost-saving points of view. It becomes possible to bake bread automatically whenever desired.
Moreover, although the kneaded material must be transferred onto an oven plate for baking, a variety of breads can be fully prepared by the cooking unit. Not only can the kneading operation, which has been a tedious operation for the user, be automatically done by the unit, but those kinds of bread that are complicated in shape and frequently required can be automatically baked.
Such a cooking unit can be used in combination with an electronic oven range or a toaster range realizing a more highly concentrated cooking apparatus.
A trough exclusively for kneading and baking ~S operations has generally had a capacity of 1-2 loaves of bread, which will be apparent from the fact that the automatic bread baking apparatus on the market is capable of baking 1-2 loaves of bread. When the trough is put in or taken out of the center of the heating chamber of an electric oven, many problems arise. The operation itself is troublesome, which can cause an erroneous operation that results in an accident or breakage of the oven, or a burn to the user. In addition, since the kneading operation requires a large rotating force with high speeds, it is necessary that the trough and the electric oven be completely secured to each other.
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It is clear that the same considerations appl~ to heating and cooking apparatus not limited to the above examples that can make rice-cakes, sourdough for cakes ~nd cookies, or can serve as a juicer or a mixer rotated at high speeds.
To enable the prior art to be explained with the aid of a diagram, the figures of the drawings will first be listed.
Fig. 1 is a perspective view of a portion of a kneading trough in a conventional heating and cooking apparatus;
Fig. 2 is a cross sectional view of a part of a heating and cooking apparatus according to one preferred embodiment of the present invention;
Fig. 3 is an exploded perspective view of a portion of a kneading trough in the apparatus of Fig. 2;
Fig. ~ is an exploded top plan view of this portion of the kneading trough in the apparatus of Fig. 2;
Fig. 5 is a cross sectional view of this portion;
Fig. 6 shows a plan view (A), a front view (B) and a partial side view (C), of a driving rotary coupling member in the apparatus of Fig. 2;
Fig. 7 shows a plan view (A), a front view (B) and a partial side view (C), of a driven rotary coupling member in the apparatus of Fig. 2;
Fig. 8 is a series of schematic views showing an installation method for the kneading trough in the apparatus of Fig. 2;
Fig. 9 is a cross sectional view of a part of apparatus according to a second embodiment of the present invention; and Fig. 10 is a perspective view of a portion of a kneading trough in the apparatus of Fig. 9.
Fig. 1 shows an example how a kneading trough is fixed to the heating and cooking apparatus in the conventional manner. The kneading trough 1 has a foot part , ~29g6~8 2, so that the trough 1 is mounted through its foot part 2 in a receiving portion 3 of a fitting 5 at the bottom of a heating chamber. Several projections 4 are formed on the foot part 2. Accordingly, when the trough 1 is placed at the bottom of the heating chamber and rotated by a predetermined angle, the projections 4 come into secure engagement with the portions 3. Since the foot part 2 is circular, a lock member 6 is provided to prevent the trough 1 from slipping off the portions 3 during rotation. The lock member 6 is movable vertically by a lever 7.
In this method for installing and securing the trough in the apparatus by rotation of the trough, both hands of the user are needed to install or detach the trough. If a series of operations, from kneading to baking, is consecutively carried out, for example, when bread is baked, the trough should be taken out of the apparatus after the bread is completely baked. When the trough is to be removed from the apparatus immediately after completion of baking, there is risk of a burn or injury to the user, since the interior of the heating chamber will be hot.
In the electric oven or the electronic oven range that can also function as a kneading device, it is so arranged that the kneading trough is fixedly accomodated in a limited space in the box-like heating chamber. The trough is inserted into the interior of the heating chamber from a lateral window, and is placed in the bottom of the heating chamber in such a manner as to be pressed down into such bottom, and then rotated for fixing. Thus, the installation method of the trough in the oven is yuite inconvenient in use. The oven can be operated even though the engagement between the trough and the main body of the oven may be insufficient, causlng an accident or a fire.
Moreover, if the inside surface of the heating chamber is coated or has undergone a surface-treatment, the coated or treated surface may be damaged by contact during the ~L299~28 engagement, resulting in an unfavorable appearance.
Further, if the receiving portion in the bottom of the heating chamber is formed of sheet metal, the end surface of the sheet metal is exposed and becomes an obstacle to cleaning, retaining residual moisture and dirt. Hands may be cut when the stains or the food residues are removed.
Accordingly, the insta]lation method of the trough by rotation is disadvantageous from the viewpoints of operating convenience, cleanliness and safety.
Moreover, with the above installation method of the trough by rotation, when the trough is installed or removed from the oven, there are large frictional forces at the engaging portions, and therefore the projections and the receiving portion become worn. The retaining force is lessened as the trough is repeatedly installed and removed, resulting in a looseness or disengagement of the trough from the oven.
Accordingly, an essential object of the present invention is to provide a heating and cooking apparatus that is so arranged that a kneading trough can be easily installed in or removed from a heating chamber.
A second object of the present invention is to provide such apparatus in which the kneading trough is easily and securely installed in or removed from the 2S heating chamber without rotating the trough.
A third object of the present invention is to ~rovide such apparatus in which the kneading trough is so engaged with the heating chamber as to be easily installed in it or removed from it in such a manner that a large rotating force from a motor, which is the driving source for kneading, is securely transmitted to a kneading vane.
A fourth object of an embodiment of the present invention is to provide such apparatus in which the kneading trough and the heating chamber are secured to each other by projecting portions aided by the force of magnetic elements, instead o~ a frictional force resulting ~Z991~Z8 from rotation, so that it becomes easy to install the trough in the heating chamber and to clean the trough.
A fifth object of an embodiment of the present invention is to provide such apparatus in which a handle is provided at a side of the trough, to enable the trough to be easily held by one hand with safety.
To this end, the invention consists of a heating and cooking apparatus comprising a heating chamber, means for heating said chamber; a kneading trough detachably installed in said chamber; a kneading vane for kneading an object in said trough; a motor for rotating said vane;
transmission means for connecting the motor to the vane: a first engagement arrangement having a strong engaging force located at an inner part of the chamber; and a second engagement arrangement which can be readily engaged and disengaged located towards an opening of said chamber, The invention also consists of a heating and cooking apparatus comprising a heating chamber, means for heating said chamber; a kneading trough detachably ~0 installed in said chamber, a kneading vane for kneading an object in said trough; a motor for rotating said vane; and transmission means for connecting the motor to the vane;
wherein at least one projection is formed in a mounting portion at the bottom of said heating chamber, and an ~S engaging portion is provided in a foot of said trough at a position corresponding to said projection to prevent the rotation of the kneading trough.
Referring to the heating and cooking apparatus shown in Figs. 2-8, an outer casing 10 supports a heating chamber 11 at the bottom of which there-is a fitting S of aluminum made by die casting and provided for mounting a kneading trough 1. There is a mounting part 3 of a generally square shape located on the fitting 5. The mounting part 3 has hole portions 12 into which projected portions 4 of a foot 2 of the kneading trough 1 are inserted. When these portions 4 are so inserted in the hole portions 12, a permanent magnet 13 in a lower part of . ~

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the fitting 5 adheres to a plate 14 of ferromagnetic material at the bottom of the foot 2. It is possible for the metal plate 14 to be located in the lower part of the fitting 5, with the permanent magnet 13 mounted in the foot 2. A handle 15 projects from a lateral surface of the kneading trough 1, so that it can be easily installed in or removed from the apparatus. Inside the kneading trough 1 there is detachably and rotatably mounted a vane 16 for kneading the material. A motor 17 transmits a rotating force, through a small pulley 18, a belt 19 and a large pulley 20, to a first rotary shaft 21. A driving rotary coupling member 32 is fixedly mounted on the first rotary shaft 21, and meshes with a driven rotary coupling member 33 integrally formed with a second rotary shaft 34 of the kneading trough 1. The force transmitted to the first rotary shaft 21 is thus transmitted to the second rotary shaft 34, thereby rotating the kneading vane 16.
The motor 17 is controlled by a control unit 22 to be rotated in a reversable or intermittent manner. Moreover, the apparatus includes an upper heater 23 at the top of the heating chamber 11 and a lower heater 24 at its bottom. These heaters 23 and 24 are operated during the fermentation and baking operations, their temperatures being controlled by the unit 22. The heaters 23 and 24 ~5 are respectively covered with an upper insulating member 29 and a lower insulating member 30 for improving the thermal efficiency. A magnetron 25 for high frequency heating emits microwaves through an opening 31 in a lateral wall of the heating chamber 11.
As is described hereinabove, since the kneading trough 1 and the portion 3 in the heating chamber 11 are generally square the conventional locking mechanism 6 is not required, there being no necessity for securing the kneading trough in pressed contact with the portlon 3. On the contrary, the kneading trough can easily be installed ~Z9~2~

in or taken out of the heating chamber 11. Moreover, the force in the direction of rotation is carried by the corners, so that the kneading trough 1 is prevented from rattling due to wear or slippage on the portion 3.
To install trough 1 in the heating chamber 11 (Fig. 8), the projected portions 4 of its foot part 2 are first inserted into the hole portions 12, using the handle 15. At this time, the portion 3 also serves as a guide frame. Thereafter~ upon moving the trough 1 down onto the fitting 5 in the heating chamber 11, the permanent magnet 13 is caused to adhere magnetically to the metal plate 14.
The trough 1 can be readily removed from the heating chamber by a reverse operation.
If the width of the portion 3 at the location nearer the door of the heating chamber is made larger than that in the back of the heating chamber, and the foot part 2 of the trough 1 is of corresponding shape, there will be sufficient room between the portion 3 and the trough 1 at the beginning of such installation. Accordingly, even if the trough 1 is installed without clear attention to its position the portion 3 will serve as a guide frame. As a result, the user is not required to give full attention to the position of the several projections as he or she mounts the trough, as in the conventional arrangement, and the installation and detachment of the kneading trough is made much simpler according to the present invention.
The trough can be readily instal-led even in the case of a box-shaped heating chamber, by sliding the trough from the front of the chamber. Accordingly, installation is convenient and free from the risk of burns to the user.
It is to be noted that the portion 3 may be formed with one or more grooves instead of the hole portions, for functioning in the same manner.
Since the handle 15 is provided on a lateral wall of the trough 1, the user can hold it with one hand.
Moreover, since the handle is secured to the trough top and i.~

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bottom, the trough is reinforced, resulting in iMproved durability.
In the foregoing embodiment, the portion 3 is made of aluminum by die casting, and therefore can readily be made in other configurations. Also, the outer peripheral surface of the portion 3 can be made smooth to avoid cutting a finger. The portion 3 is also strong, and can be made as small as possible to facilitate cleaning.
If the portion 3 is made of sheet metal, its end surface can be subjected to a smoothing treatment, and the foot part 2 of the trough 1 can be formed into a polygonal shape, such as a hexagonal shape, in order to be strong.
Further, both the fitting 5 and the portion 3 can be made of sheet metal, thus reducing work through stamping.
The description below is directed to a detection unit that is provided to detect the presence of the kneading trough, whereby to avoid imperfect engagement of the trough.
~o When the projected portions 4 are positively inserted into the hole portions 12, a detection pin 26 is depressed. This pin 26 engages a detection lever 27 (Fig.
5) to turn ON a detection switch 28. The presence or absence of the kneading trough 1 is hence detected by a signal from the switch 28. In this arrangement the driving motor 17 can be prevented from operating when the trough 1 is not present, and a heating operation can be prevented.
It can thus be positively ensured that the apparatus does not start operating unless the kneading trough is properly secured on the portion 3 in the heating chamber.
Since the detection pin 26 is provided in the fitting 5 at the bottom of the heating chamber 11, the engagement of the trough 1 with the portion 3 is firm in the vertical direction with the projected portions 4 inserted into the hole portions 12.
Fig. 9 is a cross section of a second embodiment lZ~9~2~

of the present invention, showing a cooked substance 35 in the trough 1 being taken out of the heating chamber 11 by a user 36 employing a protective glove 37. The foot 2 of the trough 1 is now secured to the portion 3 in the heating chamber ll by engagement therebetween. A lower end 41 of an operating lever 40 which forms part of the handle lS
has entered a hole 43 in the portion 3 and also a hole 38 in the foot 2 of the trough 1 aligned with the hole 43.
The upper part of the operating lever 40 is rotatably supported at a fulcrum 9 in the handle 15 and is urged by a leaf spring 42 in the counterclockwise direction. The lever 40 slides in a guide groove 39 in the handle 15. The projecting portions 4 are inserted in the hole portions 12. ~hen the user 36 grasps and squeezes the handle 15 the end 41 of the lever 40 is withdrawn from the holes 38 and portion 43, so that by elevating the handle and pulling it forwards the projections 4 are released and the user 36 can easily take the trough 1 out of the heating chamber. If the trough 1 is being installed in the ~ heating chamber, these operations are reversed.
Accordingly, as has been described above, the following advantages can be achieved by the present constructions.
(l) The kneading trough and the portion it engages in ~5 the heating chamber are both formed in a polygonal shape, so that their engagement can be easily accomplished with increased strength in the rotating direction, avoiding rattling or disengagement resulting from friction therebetween. A complicated mechanism, such as a lock mechanism or the like can be dispensed with.
(2) One side of the kneading trough is firmly secured by the engagement of at least one projected portion into a hole in the portion it engages in the heating chamber, while its other side is secured to the heating chamber magnetically. Accordingly, the kneading trough can be easily installed or removed-from the heating chamber, even ' `? `
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~Z~6;~3 when the chamber is box-shaped, and injury or burns can be avoided. When a handle is provided in a lateral wall of the trough, it can be held by one hand of the user, thus enhancing the practical efficiency.

(3) If the mounting portion in the heating chamber is formed of molded components made, for example, of aluminum die casting, its strength is increased, and the bottom of the heating chamber can be smooth, thereby increasing the convenience in cleaning and reducing the risk to the user.

(4) A detection unit ensures correct and positive operation of a detection switch, so that rotation of the motor when the trough is not present in the chamber and/or abnormal use when the trough is present, can be prevented, thus improving the safety of the apparatus.
Although the present invention has been fully described by way of example with reference to the accompanying drawings, it is to be noted here that various changes and modifications will be apparent to those skilled in the art. Therefore, unless such changes and modifications otherwise depart from the scope of the invention, they should be construed as included therein.

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Claims

1. A heating and cooking apparatus which comprises:
a heating chamber having a side opening for heating an object to be cooked therein;
a heating means for heating said heating chamber;
a kneading trough detachably installed through said side opening in said heating chamber;
a kneading vane for kneading the object to be cooked in said kneading through;
a motor for rotating said kneading vane;
a transmission means for transmitting the rotating force of said motor;
a first engagement arrangement having strong engaging force by insertion motion substantially perpendicular to the plane of said side opening and provided at the inner side of said heating chamber; and a second engagement arrangement which is easy to be engaged and disengaged and, provided at the opening side of said heating chamber.

2. A heating and cooking apparatus as claimed in claim 1, wherein said first engagement arrangement is such that a projected portion is formed in a foot part of the kneading trough in the depth side of the heating chamber, and a hole portion or a grooved portion is formed in a to-be-engaged portion at the bottom of the heating chamber in a manner to confront said projected portion, so that when said projected portion is inserted into said hole portion or grooved portion, the kneading trough is fixed to the to-be-engaged portion at one end thereof, while said second engagement arrangement is so constructed that a magnetic element is provided in the foot part of said kneading trough at the opening side of the heating chamber, and a second engaging means made of magnetic material is provided in the to-be-engaged portion at the bottom of the heating chamber in a manner to confront said magnetic element at the opening side of the heating chamber, so that said kneading trough is fixedly secured to the to-be-engaged portion through mutual magnetic force of the magnetic element and the second engaging means.

3. A heating and cooking apparatus as claimed in claim 2, wherein said second engagement arrangement is so constructed that the magnetic element in the foot part of the kneading trough is made of a ferromagnetic magnet, and the second engaging means provided in the to-be-engaged portion correspondingly to said magnetic element is made of a permanent material.

4. A heating and cooking apparatus as claimed in claim 1, wherein said first engagement arrangement is so constructed that the movable projected portion is formed in the foot part of the kneading trough and, the hole portion or the grooved portion is formed in the to-be-engaged portion correspondingly to the movable projected portion, characterized in that the engagement of the kneading trough with the to-be-engaged portion is maintained or released by the movement of said movable projected portion.

5. A heating and cooking apparatus as claimed in claim 4, wherein said kneading trough is provided with a handle at the opening side of the heating chamber when the kneading trough is laterally installed in the heating chamber, said handle being provided with an operating part so as to maintain or release the engagement between the kneading trough and the to-be-engaged portion.

6. A heating and cooking apparatus as claimed in claim 1, wherein a handle is mounted in the kneading trough at the opening side of the heating chamber when the kneading trough is laterally installed in the heating chamber, so that the kneading trough can be carried and installed in the heating chamber by the use of the handle.

7. A heating and cooking apparatus as claimed in claim 1, wherein a detection unit for detecting the presence of the kneading trough is further provided in the to-be-engaged portion correspondingly to the projected portion of the foot part of the kneading trough.

8. A heating and cooking apparatus which comprises:
a heating chamber having a side opening for heating an object to be cooked therein;
a heating means for heating said heating chamber;
a kneading trough detachably installed through said side opening in said heating chamber;
a kneading vane for kneading the object to be cooked in said kneading through;
a motor for rotating said kneading vane; and a transmission means for transmitting the rotating force of said motor;
wherein a projection is formed in a to-be-engaged portion at the bottom of said heating chamber, and an engaging portion, is provided in a foot part of said kneading trough at a position corresponding to said projection so for receiving said projection by insertion motion substantially perpendicular to the plane of said opening as to prevent the rotation of the kneading trough.

9. A heating and cooking apparatus as claimed in claim 8, wherein said foot part of the kneading trough is formed in such shape as to be partially or completely engaged with the to-be-engaged portion at the bottom of the heating chamber, characterized in that said foot part forms an engaging portion by itself to hold the kneading trough.

10. A heating and cooking apparatus as claimed in claim 9, wherein both said foot part of the kneading trough and said to-be-engaged portion in the heating chamber are formed respectively in a polygonal shape having more than four corners to hold the kneading trough.

11. A heating and cooking apparatus as claimed in claim 9, wherein said projection of the to-be-engaged portion in the heating chamber is rendered in a rail-like form to be partially or totally engaged with the foot part of the kneading trough, while serving as a guide frame when the kneading trough is installed in or removed from the heating chamber.

12. A heating and cooking apparatus as claimed in claim 9, wherein the width of the to-be-engagd portion at the opening side of the heating chamber is made larger than that at the deep side of the heating chamber, so that said to-be engaged portion is partially or totally engaged with said foot part of the kneading trough, serving as a guide frame when the kneading trough is installed in or taken out of the heating chamber.

13. A heating and cooking apparatus as claimed in claim 9, wherein the width of the to-be-engaged portion in the front-and-back direction of the heating chamber is made greatly different from the foot part of the kneading trough in the same direction, so that the foot part of the kneading trough is partially engaged with the to-be-engaged portion.

14. An installation method of the kneading trough into the heating chamber of a heating and cooking apparatus, which comprises:
a heating chamber having a side opening for heating an object to be cooked, therein a heating means for heating said heating chamber, a kneading trough detachably installed through said side opening in said heating chamber, a kneading vane for kneading the object to be cooked in said kneading trough, a motor for rotating said kneading vane and a transmission means for transmitting the rotating force of said motor, comprising the steps of:
1. inserting by insertion motion substantially perpendicular to the plane of said side opening a projected portion formed in the lower part of the kneading trough into a first to-be-engaged part in the depth at the bottom of the heating chamber so as to be coupled with each other;
2. coupling the kneading trough with a rotary driving unit by moving the kneading trough to the side of the bottom of the heating chamber;
and 3. coupling an engaging portion formed in the lower part of the kneading trough correspondingly to a second to-be-engaged part with said second to-be-engaged part provided at the opening side at the bottom of the heating chamber.